The present invention relates to color control of digital video images. In particular, this invention relates to a method of selectively controlling the intensity of a single color of a digital video image without affecting the intensities of other colors of the same image, using a digital technique.
In display of video images, color control of an image is currently performed by increasing or decreasing the saturation and/or the hue components of the chromatic part of the video image. Hereinafter, the term `saturation` refers to the intensity of a color component within the chromatic part of a video image. Saturation may also be referred to as vividness of hue. Hereinafter, the term `hue` refers to the angle between two color components within the chromatic part of a video image. Current methods of trying to control an individual color of a video image by increasing or decreasing the saturation and/or the hue components of the chromatic part of the video image result in affecting all of the colors of the same video image. It is desirable to have a method of selective, or independent, control of a single color of a video image without affecting the rest of the colors of the same video image.
A practical example of the need for selective color control is in applications using display systems which display digital video images (e.g. TV). Hereinafter, an individual color represents a linear combination of the base colors, whereby the base colors feature red. green, blue, yellow, cyan, and magenta. In such applications, a user typically desires to adjust or change an individual color of the video image, i.e., a single color component of the chromatic part of the video image, without affecting the rest of the colors of the particular video image. For example, a user may desire to adjust only one color, red, green, blue, yellow, magenta, or cyan, of a video image displayed on a TV screen, by pushing or turning the color intensity and/or color hue control button or dial on the TV system control device. Color control by this procedure affects all the colors of the TV image. And not just the single color desired to be changed by the user.
There is thus a need for, and it would be useful to have, a method of selective color control of digital video images. Moreover, there is a need for such a video image color control method which is efficient and robust for purposes of application to current digital video image display systems.
To date, this inventor is not aware of prior art teachings of a method of selective or independent color control of digital video images.